1. Field of the Invention
The invention concerns a cordless handholdable laser device featuring a sensor controlling beam activation to insure an eye safe operation.
2. The Related Art
Devices based on light amplification by stimulated emission of radiation (laser) have revolutionized many areas of dermatological medicine and of cosmetics. Amongst skin conditions responsive to treatment are acne scars, rosacea, hyperpigmentation, unwanted hair and dermal rejuvenation. Ablative resurfacing has become a common method for cosmetic rejuvenation. Wrinkle reduction has been a particular objective of the phototherapy.
Advances in laser based devices and their use in skin treatment methods have been many during the last decade. Several publications have focused on safe arming of the device to avoid unintended exposures. U.S. 2004/0167502 A1 (Weckwerth et al.) reports optical sensors for detecting engagement with a skin surface. The sensors are based upon multiple light emitting diodes, each having a unique wavelength band, and a broad-band photodetector to measure the remission of light at multiple wavelengths from a material being analyzed. U.S. 2010/0082020 (Gong et al.) describes a medical laser having a capacitance sensor and an emission control device to insure that a laser handpiece is in contact with skin prior to activation. The handpiece needs to stand perpendicular to the skin surface before any surgical operation begins.
Most electromagnetic radiation delivery devices for treatment of skin are relatively large pieces of equipment. Complexity in their basic engineering and mode of operation defeats miniaturization into a handheld device. For instance, U.S. 2008/0082089 A1 (Jones et al.) describes a system including a first solid-state and a second solid-state laser. A respective first output beam is fed into the second device for generating excitation in a rare earth doped gain medium to produce a second output beam. The latter is used to treat skin. U.S. 2007/0179481 A1 (Frangineas et al.) seeks to treat skin laxity with a plurality of pulses from a carbon dioxide laser. The system requires a housing to contain a scanning apparatus and a tip connected to a vacuum pump for exhausting smoke resulting from ablation.
Many of the reported ablative procedures require special cooling mechanisms. For instance, U.S. Pat. No. 5,810,801 directs a beam of radiation to penetrate the dermal region below a wrinkle to injure collagen. A cooling system is then activated to prevent injury of the overlying epidermis. These cooling systems are often quite bulky.
Another problem with the state of the art, particularly with portable instruments, is in their effectiveness to emit sufficiently energetic doses of electromagnetic radiation. U.S. 2011/0040358 A1 (Bean et al.) provides one solution describing a portable device which is eye safe operating between 1350-1600 nm to treat wounds and diseases. This is a battery operated system that need not directly contact tissue. A key part of the device is a lens constructed to have the laser beam converge to a focal point slightly above the tissue surface target.